Well the first track [Radio Edit version] is the version that most of us would have heard first. Its simply a shorter version of the one found on the classic album 'Music For The Jilted Generation'.
Track 2 is the Dust Brothers Remix, and its actually pretty cool - even if it does have borrowed bits from other Dust tracks.
The fourth track is the 'Original Mix' of Voodoo People and interestingly it is noticeably slower than the version most of would be used to. To me it sounds somewhat strange, but still damn fine!, and it does allow you the ability to see/hear more of what has gone into this classic dance/rave track.
But the highlight is track 3 - "Goa [The Heat The Energy Part 2]". Its a continuation of "The Heat [The Energy]" found on 'Jilted' and I am dumbfounded why they never included this on the album. Its got an awesome rich acid line running through it while using the beats etc from Part 1. Its simple but effective. Its not a better track than Voodoo People, but it is a great b-side.
Basically, if you want to buy a Prodigy CD single, make it this one.